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derwood,

Well done. Before anything else I'd shoot for an engine that will run until the heat source is removed. If ya gotta build a cooling system for it oh well. The idea, for me, is to build an engine that will work every time for a long time. My Coleman lantern globe gamma engine will run all day. I find that noise is a indicator of balance issues on the engines I've built. Try advancing or retarding the optimal crank angle balance point a tiny bit and see if that click goes away. AS Ian has said a drop of good oil might deal with that.

Keep up the good work, and thanks for sharing!
R

Thanks for the support everyone.

You could try a fan, make a shroud around the area requiring cooling, cardboard, glue, and adhesive tape will do for a trial run, I'v used a centrifugal type fan, and a cardboard shroud, and it worked very well, when you have proved it, you can make it up out of tin, in fact, a large tin can would make a good basis for the cylinder shroud, or go for water, much more efficient. Ian S C

This engine will mount to my rocket stove very soon. I am thinking of making a shroud and using the fresh air intake of the stove to pull air through the shroud.

This is the latest configuration. I have not fired it up yet but I am confident that it will run very well. The heat tube and cylinder portion are basically the finished product. A water cooled cylinder can be added later. The crank shaft and case are just a work in progress. The case will eventually be sealed for pressurized testing. I still have some balancing issues but it is balanced good enough to test run. I need to come up with a good propane heater configuration. The heat tubes are 4.5 inches center to center and the tubes are 2inch OD. Any suggestions for heater design would be appreciated.

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First test run video.
http://youtu.be/wtW9fYVFXOY

derwood wrote:First test run video.
http://youtu.be/wtW9fYVFXOY

Wow! looks like it has quite a bit of power.

Have you tried putting a load on it yet?

I tested a single cylinder version and it produced 10 watts. Unfortunately it loses power quickly when under a load. I have tried cooling the cylinder but it only helps a little bit. I think the inner tube needs cooling. I am trying to come up with a practical way to cool the inner tube.

@derwood
I think your engine is awesome. I downloaded your zipped plans, looked them over, and was disappointed. Disappointed because the engine build is way beyond my pay grade and capabilities to build. It looks like a jet engine inside. Was the original build this complicated? The video's on you tube show a very powerful and fast engine, I'm impressed.
I too think a diaphram version would be worthwhile.
If your original version is depicted in a video and has ss wool, and is easier to build I would attempt it.
I've seen a lot of engines on youtube and this one is a top notch design.
If you have a version that has a traditional lamina flow design I would like those plans.

For a gas burner you could try a Bunsen type with a T on the end, and the burners at the end of the wings of the T.
For external cooling, it looks as though you need to either put a shroud around the finned area, and a fan to blow air through the fins, perhaps blown into the centre between the cylinders, over the top, and out the sides. Or water jackets and water cooling.
Crazyguy, there is another way of taking power off one of these motors, forget about a crankshaft, and use a free piston, this will oscillate, and if you fit a magnet on the end of the piston, and put the magnet inside a coil of wire, you have a linear alternator, and it doesn't have to be very big to light up an LED.
Ian S C

@derwood
Do you have a drawing?
@ IANsc
Yes I was impressed by the video without a crank/flywheel. But arent they harder to get going?

Derwood
So if cooling doesnt help much then i think the central pipe should be removed as it seems it's conducting heat to the cold side. And go back to a regular stack. Then cooling should work.

no, that's not the problem. there needs to be two cold ends and the inner tube end cant be cooled properly. I have built a new design that works quite well.

crazyguy, the engine design that I shared will work with or without a crank shaft

@derwood
I like the single cylinder model, i think it works well. Your plans don't describe the fabrication of the pointed end of the inner pipe. Are both ends of the inner pipe closed? Is the pointed end solid metal? How far back is it solid?
I don't understand the statement " two cold ends" It looks like the flame is applied to the one end and the piston is at the other end.
Could you share with us the new design that works quite well?. I am very interested in this engine.


Are you displaying this engine at any event in the U.S.A. ?